Nova Scotia

Scientists predict record ocean temperatures in 2012

Dave Hebert, a research scientist with the Bedford Institute of Oceanography, said temperatures off Nova Scotia in August were about two degrees above normal.
Researchers say they're seeing southern fish species - such as this Triggerfish - swimming in northern waters. (Bob Semple)

Canadian and U.S. scientists are predicting 2012 will set records for warm ocean temperatures on the eastern Seaboard.

Dave Hebert, a research scientist with the Bedford Institute of Oceanography, said temperatures off Nova Scotia in August were about two degrees above normal.

"We're actually seeing it in all the Gulf of St. Lawrence, the Scotian Shelf all the way up to the Labrador Shelf. All warming up a couple of degrees," Hebert told CBC News.

He said the department of fisheries and oceans has not yet calculated temperatures for 2012, however he expects it to break records.

Dave Hebert expects 2012 to be the warmest year since temperatures were recorded. (CBC)

"The last two years have been the warmest years since we've started measuring. So, I think this year being even warmer than last year, I think this year will probably be the warmest we've had."

This week, the National Oceanic Atmospheric Administration in the U.S. reported the highest water temperatures ever off New England were recorded in the first six months of 2012.

"We were really struck at how warm the shelf had become," said Kevin Friedland of the Northeast Fisheries Science Centre.

The agency reported on temperatures on the Northeast Continental Shelf from Cape Hatteras, North Carolina to the Gulf of Maine.

"Not only were they top to bottom very warm, but spatially. We see the extent of the warming really covered the shelf where there is high productivity in fishing... also seaward out to the Gulf Stream. It was pervasive," Friedland said in an interview from Narraganset, Rhode Island.

Fish migration changing

The NOAA study also reported a northward shift of cod. Scientists on both sides of the border are watching for southern fish species to follow warm water north. Friedman is concerned one of the losers in the climate change may be the Atlantic salmon.

"When the fish migrate from fresh water, they will be entering a much warmer ocean with a more aggressive predator field so that the warmer it gets there would be higher mortality occurring on these stocks," said Friedman. "So this will be a cascading effect most acutely felt in the Gulf of Maine to Nova Scotia and the major salmon producing areas such as the Gulf of St. Lawrence."

In Canada, scientists tell CBC they are trying to sort out what this means.

"If we get systematic changes in temperatures, we can expect the animals to pick new places to live," said Charles Hannah, a research scientist and manager with the department of fisheries and oceans in Halifax.

But he said it's impossible to predict the immediate effects of the warmer water seen in recent years.

In the 1950's, water temperatures off the east coast of Canada also spiked and were followed by about a decade of cooling.

"When you filter out the noise - the decadal variabilities - there is a long term trend and this years' temperatures are consistent with that trend," Hannah said.

"But it's quite possible and likely that next year or the year after we could have a reversal and the temperatures could decline for a few years. Predicting distributions of animals for next year or the following year are really difficult because we can't say it will necessarily will be warmer next year."

The DFO is in the second year of a five-year program examining the impact of ocean climate change. It's a national project called the Aquatic Climate Change Adaptation Services Program.

"Its purpose is to try to help us understand what's going to happen from the physics to the biology of the animals in the ocean to how climate change will impact DFO's activites," said Hannah.